Frequency Glossary

Summary: This glossary will serve as a guide o the various terms associated with the use of frequencies and the devices that are dependant upon them.

Learning About Frequencies and the Devices That Use Them
	Frequencies Glossary Advances in electricity, electronics and new technology require the use of frequencies to enable the associated devices to function and perform a specific task. Because of this frequencies are all around us. This glossary will serve as a guide o the various terms associated with the use of frequencies and the devices that are dependant upon them.

Antenna: A wire or set of wires used to send and receive radio waves.

Cell Phone: A wireless telephone that sends and receives messages using radio frequency energy in the 800-900 megahertz portion of the radio frequency (RF) spectrum.

Cell Site: Another name for a cellular base station.

Cellular Base Station: Antennas and electronic equipment used to receive and transmit cellular telephone signals.

Cordless Telephone: A portable telephone that transmits signals over a small distance to a receiver that is wired into the telephone network. Cordless telephones are generally used only in or around one’s home.

Electromagnetic Energy: Waves of electrical and magnetic energy moving together through space. Also called electromagnetic radiation.

Electromagnetic Field: An area containing electromagnetic energy (electromagnetic radiation).

Electromagnetic Radiation: Waves of electrical and magnetic energy moving together through space. Also called electromagnetic energy.

ERP (Effective Radiated Power) - A measure of how well an antenna concentrates the radiated energy in a specific direction. An analogy can be drawn in a comparison between an ordinary light bulb and a spotlight. At a given distance, the light that falls on a surface in the beam of a 100 W spotlight is much brighter than that from an ordinary 100 W bulb at the same distance, because the spotlight concentrates the light into a beam. Correspondingly, the light that falls on a surface that is not in the beam of the spotlight is much less than that from the ordinary light bulb at the same distance.

Frequency: The number of waves passing a given point in one second. Measured in Hertz (Hz), or cycles per second.

Hertz: The unit of measurement used to describe the frequency of a wave. One Hertz (Hz) is equal to one cycle of the wave per second.

Microwave (MW) - An electromagnetic wave with a wavelength between about one millimeter and 30 centimeters corresponding to a frequency between 300 GHz and 1 GHz.

Microwaves: A subset of radio waves that have frequencies ranging from around 300 million waves per second (300 MHz) to three billion waves per second (3 GHz).

Radio Frequency (RF) - frequencies of electromagnetic waves between approximately 3 kHz (3,000 Hz) and 300 GHz (3 x 1011 Hz). Sometimes, a distinction is drawn between radio waves, which have frequencies between 3 kHz and 1 GHz, and microwaves, which have a frequency between 1 GHz and 300 GHz.

Radio Waves: Electromagnetic energy with frequencies in the 3000 hertz (3 kHz) to 300 billion Hertz (300 GHz) portion of the electromagnetic spectrum.

Radio frequency Energy: Another name for radio waves.

RF Energy: An abbreviation for Radio Frequency Energy.

Telecommunications: The transmission of words, sounds, or images, usually over great distances, in the form of electromagnetic energy, for example by telegraph, telephone, radio, or television.

Wireless Telephone: A hand-held phone with a built-in antenna that transmits signals through the air without a physical connection. Cell (cellular), PCS, mobile, car, and bag (transportable) phones are all considered wireless telephones. Cordless telephones used only in or around one’s home are not considered wireless telephones.